/// <summary>
/// Sets up a new reaction pipeline on a component that implements INotifyPropertyChanged. This is
///
/// This method is provided for interop on platforms that dont support the ExpandoObject (dynamic) ie. Xamarin.iOS
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source"></param>
/// <param name="observeInitial">If the subscription will be alerted as soon as its made, no property change is required</param>
/// <param name="scheduler"></param>
/// <param name="properties">The properties to watch for changes to</param>
/// <returns>A dictionary with the propertName as the key, and property value which u will need to cast to whatever type they are supposed to be</returns>
public static IObservable <Dictionary <string, object> > OnReaction <T>(this T source, bool observeInitial,
IScheduler scheduler, params Expression <Func <T, object> >[] properties) where T : INotifyPropertyChanged
{
return(RxObservable.DfrCreate <Dictionary <string, object> >(o =>
{
try
{
var propertyNames = new Dictionary <string, Func <T, object> >();
Func <Dictionary <string, object> > GetValues = () =>
{
var d = new Dictionary <string, object>();
foreach (var p in propertyNames)
{
d[p.Key] = p.Value.Invoke(source);
}
return d;
};
foreach (var property in properties)
{
propertyNames.Add(property.GetPropertyInfo().Name, property.Compile());
}
var sub = IObservableExtensions
.FromPropertyChanged <PropertyChangedEventHandler, PropertyChangedEventArgs>(
handler => handler.Invoke,
h => source.PropertyChanged += h,
h => source.PropertyChanged -= h)
.Where(e => propertyNames.ContainsKey(e.EventArgs.PropertyName))
.Select(e => GetValues());
if (observeInitial)
{
sub = sub.StartWith(GetValues());
}
return sub.Subscribe(o);
}
catch (Exception e)
{
o.OnError(e);
return Disposable.Empty;
}
})
.ObserveOn(scheduler)
.SubscribeOn(scheduler));
}
/// <summary>
/// Sets up a new reaction pipeline on a component that implements INotifyPropertyChanged. Typically this is followed by an action to be taken
/// when TStuff occours
///
/// advanced: its a simple fluent wrapper for Input.ObserveOn
/// </summary>
/// <typeparam name="TStuff"></typeparam>
/// <param name="stream">An observable you want to use as a quasi reaction component</param>
/// <param name="scheduler">The scheduler tha the pipeline will use for work. Defaults to OnReactionScheduler</param>
/// <param name="properties">The properties too watch for changes. The properties can then be referenced by name on the returned dynamic object</param>
/// <returns>A dynamic object with the properties and their values attached. Reference them by the same name</returns>
public static IObservable <dynamic> OnReactionTo <T>(this T source, IScheduler scheduler,
params Expression <Func <T, object> >[] properties) where T : INotifyPropertyChanged
{
return(Observable.Create <dynamic>(o =>
{
try
{
var propertyNames = new Dictionary <string, Func <T, dynamic> >();
foreach (var property in properties)
{
propertyNames.Add(property.GetPropertyInfo().Name, property.Compile());
}
return IObservableExtensions
.FromPropertyChanged <PropertyChangedEventHandler, PropertyChangedEventArgs>(
handler => handler.Invoke,
h => source.PropertyChanged += h,
h => source.PropertyChanged -= h)
.ObserveOn(scheduler)
.Where(e => propertyNames.ContainsKey(e.EventArgs.PropertyName))
.Select(e =>
{
dynamic d = new ExpandoObject();
foreach (var p in propertyNames)
{
((IDictionary <string, object>)d)[p.Key] = p.Value.Invoke(source);
}
return d;
})
.Subscribe(o);
}
catch (Exception e)
{
o.OnError(e);
return Disposable.Empty;
}
}));
}
